docs: def glob_if_windows_os(path, exact_num_args=False):
      """Expands any globbing if system_os is Windows (DOS doesn't do it).  The
      argument exactNumFiles can be set to an integer to check for an exact
      number of matching files.  Returns a list."""
      if system_os != "Windows": return [path]
      globbed = glob.glob(path)
      if not globbed:
          print("\nWarning in pdfCropMargins: The wildcards in the path\n   "
                + path + "\nfailed to expand.  Treating as literal.",
                file=sys.stderr)
          globbed = [path]
      if exact_num_args and len(globbed) != exact_num_args:
          print("\nError in pdfCropMargins: The wildcards in the path\n   "
                + path + "\nexpand to the wrong number of files.",
                file=sys.stderr)
          cleanup_and_exit(1)
      return globbed